In the art of building construction it is common practice to cast the base or foundation with concrete. Cast-in-place concrete walls or masonry walls are commonly constructed by using concrete forms. Concrete forms act as molds to shape and support concrete until the concrete cures sufficiently to stand without the forms. These concrete forms are typically made from wood, metal or plastic, and can range in height from 4 inches to many feet. Wood forms are often plywood or oriented strand board (OSB. It is common practice for contractors to reuse wood forms in multiple projects. Reusable wood forms are acceptable until they become too flexible to hold the concrete at the right lines. One drawback is that the surfaces of reusable wood forms are required to be checked closely for old concrete and surface defects, which can become burdensome and time consuming.
A conventional wood form consists of assemblies of about 4 ft by 8 ft plywood sheets that have been braced vertically by studs and horizontally by spreader bars. A contractor typically uses wood form panels to erect and position a panel on each side of an identified frame to construct the formwork. The panels are typically held in place with 2×4 members or studs against the ground. Contractors most commonly attach these panels to the footboards with screws or nails. In addition to having the wood form panels and footboards, a contractor may also use 2×4 spreaders and/or struts to maintain the interior dimension of the formwork. The spreaders are used most often in tall, narrow wall forms. These spreaders are mostly placed across the wood form panels and nailed thereon to create multiple cavities within the formwork and to construct a temporary frame for pouring the concrete.
In constructing a concrete or masonry wall, contractors place reinforcing rebar inside the wood forms. The reinforcing rebar is laid along the bottom of the formwork and is usually spaced apart slightly from the ground and a grid extends throughout the foundation and walls. The reinforcing steel is commonly held in place by fastening the bars with approved wire ties. In addition to the steel, dowels or vertical bars are commonly used to connect sections of the substructure together, forming an integral unit. These dowels tie a footing into a wall or column. The bottom ends of the dowel are typically L-shaped and become embedded in the formwork when the concrete is poured for the foundation. The dimensions of the dowels may vary upon the type and size of the wall or column being constructed.
An ongoing concern in concrete construction is maintaining the rebar dowels embedded in the foundation and extending from the upper surface in the proper position and orientation during a concrete pour. To help address this problem, contractors have attached additional 2×4's across the spreader bars used to maintain the interior dimensions of the form to support the dowels. The wood forms are typically nailed to the spreader bars. A contractor can then tie the dowels to the wood forms using a nail and bending the nail around the dowel such that the dowel is secured to the wood form. The additional pieces of plywood help provide a structure to support the dowels. Once the concrete is poured, it is allowed to cure before any further work is performed. Therefore, horizontal reinforcement bars are not installed on the dowels until after a several hours of curing the concrete. Therefore, one drawback to this process is the delay in the installation while waiting for the concrete to cure, which can take at least a couple of hours. Another drawback to this construction process is the amount of wood material wasted because of defects in the wood resulting from concrete exposure. Another drawback is the time consuming and laboring consuming tasks of removing and attaching nails from all the wood form during installation and demolition of the formwork.
There is a need for a much simpler process for constructing concrete walls or masonry walls that requires less demolition and installation time. There is a need for a system that allows for horizontal reinforcement bars to be installed on embedded vertical elements without having to wait hours for concrete to cure. There is a need for a system that produces less waste material when constructing a concrete foundation. The present invention addresses these as well as other problems associated with concrete foundations and walls.